The present invention relates to an encryption method and a data delivery system for encrypting data to be encrypted, and in particular, to the encryption method and data delivery system capable of effectively encrypting the data to be encrypted.
As for a monitoring system for a security purpose, it is becoming essential, for instance, to construct a system using a network such as the internet in terms of cost-competitiveness and differentiation from a conventional system. In the case of an open network such as the internet, dangers of eavesdropping, data tampering and so on are increasing.
Here, cryptography and message authentication are known as countermeasure technologies against the eavesdropping and data tampering on the network. For instance, the RFC (Request for Comments) 3711 which is a standard of the technologies relating to the internet introduces RTP (Real-time Transport Protocol) packet cryptography and message authentication technologies.